In June 2007, ARM led the multi-agency Cloud and Land Surface Interaction Campaign (CLASIC) conducted at the ARM Southern Great Plains site. With scientists beginning to analyze the data, the Cooperative Institute for Mesoscale Meteorological Studies at the University of Oklahoma hosted a workshop on March 26-27 for participants of CLASIC and others interested in the data collected. The purpose of the workshop, chaired by CLASIC principal investigator Mark Miller, was to discuss the availability and quality of data collected during CLASIC, review initial results, and coordinate followup research efforts. The workshop agenda also included time for presentations and discussions on topics of general interest to the CLASIC community. A key consideration of the 20-member group was the potential for a future experiment to address CLASIC science questions that were compromised by the flooding that occurred in Oklahoma during the June 2007 campaign.

Despite record-setting rainfall during that month, several of the science objectives related to cloud property measurements were attained. The workshop participants reviewed high quality data sets of fair weather cumulus, stratus, and deep convection collected by the ER-2, Twin Otter, Duke Helicopter, and many other aircraft during CLASIC. They also looked at high quality data from two prototype radar systems, as well as detailed measurements of the surface fluxes and land surface characteristics at multiple sites around the SGP domain. A companion experiment sponsored by the DOE Atmospheric Science Program targeted aerosol processing in cumulus clouds. Because of the timing and complementary nature of the two efforts, this campaign, called the Cumulus Humilis Aerosol Processing Study, or CHAPS, was also discussed at the Workshop.